为了获取三芯光纤复合海底电缆超负荷运行时的温度变化情况，分别建立了三芯海缆陆地段与海底段的有限元模型。通过ANSYSY软件稳态仿真验证了所建模型进行超负荷运行的可行性。将120%、140%、160%、180% 和200%的载流量分别施加到陆地段和海底段海缆模型上，陆地段比海底段先达到海缆最高工作温度90 ℃，并给出了不同负荷运行情况下的应急时间。超负荷值较低时，海底段海缆应急时间大于陆地段应急时间，且应急时间随超负荷值的增大逐渐逼近。该结论为利用光纤传感监测海缆过负荷运行提供了参考。

In order to obtain the temperature change of the three-core fiber composite submarine cable overload operation condition, the finite element of three-core cable section and the section of the land sea model are established respectively. The feasibility of the model is verified by ANSYSY simulation. 120%, 140%, 160%, 180% and 200% of the carrying capacity are applied to the land and submarine cable model. It shows that the land cable model first reaches the highest ratio of submarine cable temperature 90 ℃. We also provide the emergency time in different load conditions. When the three-core cable overload in the lower case, the emergency time period in the submarine is longer than that in the landing area. The emergency time difference becomes smaller with the increase of load value. Our investigation provides a reference value for overload operation by the optical fiber sensing monitoring cable.